This proposal seeks to establish the neuromuscular characteristics of the urinary bladder during the storage and voiding phase. The interplay between the mechanical and electrical properties of the detrusor with respect to bladder pressure and volume will be explored in vivo using implantable miniature force transducers and macroelectrodes. This exploration will focus upon the regional distribution and symmetry of electromyographic and mechanical activity in the trigonal, middle and dome of the bladder. Simultaneously, recorded data from each region will be compared with urethral and anal sphincter electromyography and associated urodynamic parameters. Data obtained will be analyzed to derive the mechanism by which electrical excitation is spread around the bladder. Particularly emphasis will be placed upon the distribution of regional electrical and mechanical activity to factors such as stimulated and spontaneous detrusor contraction. Hypogastric nerve stimulation will be used to elicit contraction, and pelvic nerve stimulation to produce inhibition of bladder contractions. The timing and transit time of nerve and muscle stimulation will also be measured to derive the spatial distribution of electrical and mechanical excitation to the detrusor. In addition, these parameters will be evaluated in obstructed bladder at various degrees of muscle hypertrophy. On the basis of the data obtained, an electromyographic mapping of the bladder will be synthesized which will characterize the waveform, spike frequency and transmit times as a function of bladder volume and pressure. It is anticipated that the results of this investigation will provide approaches towards a better understanding of the mechanism of bladder function and generate supporting data that will contribute to the interpretation of detrusor electromyography as a clinical tool.